Methods and systems for ignition of a smoke unit fuel source

ABSTRACT

In an aspect, data characterizing a plurality of measurements of a rate of energy supplied to an igniter of a smoke unit and of a temperature of a region proximate the igniter, acquired during a predetermined period of time of igniter activation, can be received. A maximum time of igniter activation can be determined based on an average rate of energy supplied to the igniter and an average temperature of the region proximate the igniter. Whether a total length of time, during which the igniter is activated and during a subsequent period of time, exceeds the maximum time of activation can be determined, and the igniter can be deactivated in response to determining that the total length of the time exceeds the determined maximum time of activation.

FIELD

A grill system including a smoke unit, and methods for initiating thecombustion of fuel contained therein and controlling the delivery ofpower to inductive loads are provided.

BACKGROUND

Smoke can be used in a variety of cooking devices and with a variety ofcooking operations to impart flavor. As an example, grills and grillingdevices can come equipped with smoking capabilities, or the means withwhich to impart smoke flavor into food cooked with these grills andgrilling devices. However, electric cooking appliances may only be ableto impart limited smoke flavor or no smoke flavor into food cookedtherewith. Further, in grilling systems which impart smoke flavor intofood, control of the smoke output can be challenging.

Additionally, the quality of the smoke output can depend on how the fuelsource used to generate the smoke is ignited. For example, if the fuelsource is over-ignited by an igniter, the ignitor can provide anexcessive amount of energy to the fuel source, such that there is toomuch combustion for the amount of airflow within the system and notenough oxygen supply to sustain a clean and efficient burn. For example,if the fuel source is under-ignited by the igniter, the igniter canprovide too little energy to the fuel source, such that there is not alarge enough ember generated to ensure a self-sustained combustionreaction that will spread throughout the rest of the fuel source in aconsistent manner. In order to generate optimal smoke production forcooking, there is an ideal range of energy that must be provided to thefuel source from the ignitor such that there is just the right amount ofheat to create a sustained combustion reaction, but not so much thatcombustion region starves itself of oxygen or burns through a fuelsource more vigorously than intended.

However, reliably monitoring the performance of the fuel source ignitionprocess, such that it results in optimized smoke production for cooking,can be difficult due to the nature of the perceivable outputs fromcombustion. For example, the physical outputs resulting from combustionof the fuel source are heat and combustion products such as smokecompounds or CO₂—therefore, in order to achieve closed loop control forcombustion, a given control system must be able to detect those outputsfrom combustion in a statistically significant way. However, designing asystem that would be cost effective and reliable enough to detect eitherof these outputs can be impractical. Additionally, closed loop controlfrom the perspective of detecting combustion products as an input canalso be challenging because it can be infeasible or impossible toimplement a sensor that is safe, cost effective, and able to withstandthe operating environment of a smoke unit.

Inductive loads such as shaded-pole motors are used to operate varioustypes of devices such as exhaust fans, cooling fans, table fans,hairdryers, relays, and air conditioners. Shaded-pole motors are oftencoupled with Triodes for Alternating Currents (TRIACs) to modulate theoperating speed of fans primarily because these motors are robust, costeffective, and reliable. However, the performance of these motors isadversely affected by several factors such as, e.g., variations insupply voltages, a low power factor, low initial torque when devices areturned on, inefficiency due to the presence of a shading coil, and soforth.

Accordingly, there remains a need for improved systems and methods forignition of a smoke unit fuel source and improving the accuracy withwhich the operating speeds of various devices are modulated based onpower delivered to the motors of these devices.

SUMMARY

A cooking device, a smoke unit, and methods of cooking food using acooking device with a smoke unit are provided. Related apparatuses andtechniques are also described.

In one aspect, a cooking device is provided and can include a housinghaving a base defining a hollow cooking chamber and a movable covercoupled to the base. The movable cover can be configured to cover anopening in the housing to the hollow cooking chamber. In someembodiments, the movable cover can be in the form of a lid or door. Thecooking device can also include a smoke unit coupled to the housing, andthe smoke unit can include a fuel box defining an interior chamber influid communication with the hollow cooking chamber. The smoke unit canalso include an igniter proximate the fuel box and configured to ignitefuel contained in the fuel box. The cooking device can also include anelectronic controller in operable communication with the igniter. Theelectronic controller can be configured to determine an average rate ofenergy supplied to the igniter during a predetermined period of time ofactivation of the igniter and during an initial ignition operating modeof the igniter, determine an average temperature of a region proximatethe igniter during the predetermined period of time, and adjust amaximum time of activation of the igniter when the igniter is operatingin the initial ignition operating mode during a subsequent period oftime following the predetermined period of time based on the determinedaverage rate of energy and the determined average temperature. In someembodiments, the electronic controller can be configured to adjust themaximum time of activation of the igniter based on an operating mode ofthe smoke unit.

While the cooking device can have a variety of configurations, in someembodiments, the cooking device can include a fan coupled to thehousing, in fluid communication with the fuel box, and in operablecommunication with the electronic controller, and the electroniccontroller can be configured to adjust an amount of power delivered tothe fan during the initial ignition operating mode. In some embodiments,the electronic controller can be configured to adjust the amount ofpower delivered to the fan when a difference between a temperature ofthe region proximate the igniter and a temperature of air within thehollow cooking chamber is less than or equal to a predeterminedtemperature difference threshold. In some embodiments, the electroniccontroller can be configured to adjust the amount of power delivered tothe fan when the temperature of the air within the hollow cookingchamber is less than a predetermined temperature threshold. In someembodiments, the electronic controller is configured to adjust theamount of power delivered to the fan when the rate of energy supplied tothe igniter is less than a predetermined threshold. In some embodiments,the movable cover can be in the form of a lid or door.

In another aspect, a system is provided and can include at least onedata processor and memory storing instructions, which when executed bythe at least one data processor, cause the at least one data processorto perform operations including receiving data characterizing aplurality of measurements of a rate of energy supplied to an igniter ofa smoke unit and of a temperature of a region proximate the igniter,each of the plurality of measurements acquired during a predeterminedperiod of time during which the igniter is activated and during aninitial ignition operating mode of the igniter; determining, based onthe received data, an average rate of energy supplied to the igniterduring the predetermined period of time and an average temperature ofthe region proximate the igniter during the predetermined period oftime; determining, based on the determined average rate of energysupplied to the igniter and the determined average temperature of theregion proximate the igniter, a maximum time of activation of theigniter when the igniter is operating in the initial ignition operatingmode; determining whether a total length of time during which theigniter is activated exceeds the maximum time of activation; and causingthe igniter to deactivate in response to determining that the totallength of the time exceeds the determined maximum time of activation.

One or more of the following features can be included in any feasiblecombination. For example, the operations can further include receivingsecond data characterizing an operating mode of the smoke unit, and themaximum time of activation can be determined based on the receivedsecond data. For example, the operations can further include receivingthird data characterizing a temperature of the air within a hollowcooking chamber in fluid communication with the smoke unit, anddetermining, based on the received third data, whether the hollowcooking chamber is in a cold temperature state. For example, theoperations can further include receiving fourth data characterizing atemperature of the region proximate the igniter; and the determining ofwhether the smoke unit is in a cold temperature state can includedetermining whether a difference between the temperature of the regionproximate the igniter and the temperature of the air within the hollowcooking chamber is less than or equal to a predetermined temperaturedifference threshold. For example, the determining of whether the smokeunit is in a cold temperature state can include determining whether thetemperature of the region proximate the igniter is less than apredetermined temperature threshold. For example, the determining ofwhether the smoke unit is in a cold temperature state can includedetermining whether the temperature of the air within the hollow cookingchamber is less than the predetermined temperature threshold. Forexample, the operations can further include in response to determiningthat the smoke unit is in a cold temperature state, determininginstructions for operating a fan in fluid communication with the smokeunit in a fan compensation mode; and providing the instructions to acontroller of the fan to cause the fan to operate in the fancompensation mode.

In another aspect, data characterizing a plurality of measurements of arate of energy supplied to an igniter of a smoke unit and of atemperature of a region proximate the igniter can be received. Each ofthe plurality of measurements can be acquired during a predeterminedperiod of time during which the igniter is activated and during aninitial ignition operating mode of the igniter. An average rate ofenergy supplied to the igniter during the predetermined period of timeand an average temperature of the region proximate the igniter duringthe predetermined period of time can be determined based on the receiveddata. A maximum time of activation of the igniter when the igniter isoperating in the initial ignition operating mode can be determined basedon the determined average rate of energy supplied to the igniter and thedetermined average temperature of the region proximate the igniter.Whether a total length of time during which the igniter is activatedexceeds the maximum time of activation can be determined. The ignitercan be deactivated in response to determining that the total length ofthe time exceeds the determined maximum time of activation.

One or more features can be included in any feasible combination. Forexample, second data characterizing an operating mode of the smoke unitcan be received, and the maximum time of activation can be determinedbased on the second received data. For example, third datacharacterizing a temperature of the air within a hollow cooking chamberin fluid communication with the smoke unit can be received, and whetherthe smoke unit is in a cold temperature state can be determined based onthe received third data. For example, fourth data characterizing atemperature of the region proximate the igniter can be received, and thedetermining of whether the smoke unit is in a cold temperature state caninclude determining whether a difference between the temperature of theregion proximate the igniter and the temperature of the air within thehollow cooking chamber is less than or equal to a predeterminedtemperature difference threshold. For example, the determining ofwhether the smoke unit is in a cold temperature state can includedetermining whether the temperature of the region proximate the igniteris less than a predetermined temperature threshold. For example, thedetermining of whether the smoke unit is in a cold temperature state caninclude determining whether the temperature of the air within the hollowcooking chamber is less than the predetermined temperature threshold.

In one aspect, a device is provided and can include a power sensor, atemperature sensor, a triode for alternative current (TRIAC), aninductive load, and an electronic controller that includes memory. TheTRIAC can be in operable communication with the electronic controllerand the inductive load. The power sensor is in operable communicationwith the electronic controller and is configured to detect datarepresentative of an electrical value. The electronic controller isconfigured to access, from the memory, a target value for the inductiveload based on the electrical value, implement a transfer function basedalgorithm for determining a set point value using the electric value,apply the set point value on the TRIAC, and adjust operation of theinductive load to the target power responsive to the application of theset point value on the TRIAC, the operation of the inductive load at thetarget power causes the operation of the inductive load at the targetvalue.

In some embodiments, the device may further comprise a fan including atleast one fan blade that is operably coupled to the inductive load. Insome embodiments, the inductive load can be a shaded-pole motor thatcontrols rotational speed of the at least one fan blade disposed on thefan. Further, the implementing of the transfer function based algorithmcan be based on at least one transfer function. The at least onetransfer function can be based on a linear relationship between aplurality of power values of the inductive load at the electrical valueand a plurality of speeds of the inductive load the electrical value. Itis noted that the target value is a target speed.

The at least one transfer function enables mapping a plurality of speedsof the inductive load relative to the electrical value with theplurality of power values at the electrical value. The target speed isincluded in the plurality of speeds and the target power is included inthe plurality of power values. The electrical value is a supply voltage,a current, or a power. In some embodiments, the adjusting of theoperation of the inductive load can include increasing an amount ofpower delivered to the inductive load from a current power to the targetpower. In other embodiments, the adjusting of the operation of theinductive load can include decreasing an amount of power delivered tothe inductive load from a current power to the target power.

In some embodiments, the electronic controller is further configured todetermine, using the temperature sensor, a current temperature of theinductive load, compare the current temperature to a thresholdtemperature range, wherein the threshold temperature range is from 15°C. to 50° C., and initiate a starting condition compensation algorithmresponsive to the current temperature being within the thresholdtemperature range or below the temperature threshold range. Theinitiation of the starting condition compensation algorithm can includeapplying a decaying value to a starting power, and driving the inductiveload with the starting power, upon which the decaying value is applied,for a predetermined time frame.

In another aspect, a method implemented by a controller is provided andcan include receiving an electrical value. Further, a target value foran inductive load that is based on the electrical value may be accessedby the controller via the memory of the controller, a transfer functionbased algorithm the set point value can be applied on a triode foralternating current (TRIAC). Additionally, operation of the inductiveload may be adjusted responsive to the applying of the set point valueon the TRIAC. The operation of the inductive load at the target powercauses operation of the inductive load at the target value. In someembodiments, the inductive load can be a shaded-pole motor that iscoupled to a fan.

In yet another aspect, a system is provided and can include a powersource, a temperature sensor, a triode for alternative current (TRIAC),an inductive load, and at least one data processor that iscommunicatively coupled to the TRIAC. The at least one data processorcan store instructions, which when executed by the at least one dataprocessor, causes the at least one data processor to perform variousoperations. One or more of the following features can be included in anyfeasible combination. For example, the operations can includedetermining an electrical value, accessing a target value for theinductive load that is specific to the electrical value, implementing atransfer function based algorithm for determining a set point valueusing the electric value, applying the set point value on the TRIAC, andadjusting operation of the inductive load to the target power responsiveto the applying of the set point value on the TRIAC, the operation ofthe inductive load at the target power causes operation of the inductiveload at the target value.

In some aspects, the operations further comprise determining, using thetemperature sensor, a current temperature of the inductive load, andcomparing the current temperature to a threshold temperature range,wherein the threshold temperature range is from 15° C. to 50° C., andinitiating a starting condition compensation algorithm responsive to thecurrent temperature being within the threshold temperature range orbelow the temperature threshold range.

The details of one or more variations of the subject matter describedherein are set forth in the accompanying drawings and the descriptionbelow. Other features and advantages of the subject matter describedherein will be apparent from the description and drawings, and from theclaims.

BRIEF DESCRIPTION OF DRAWINGS

These and other features will be more readily understood from thefollowing detailed description taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a front perspective view of a cooking device according to anembodiment;

FIG. 2 is a rear perspective view of the cooking device of FIG. 1 ;

FIG. 3A is a perspective view of another embodiment of a cooking device;

FIG. 3B is a cross-sectional view of the cooking device of FIG. 3A;

FIG. 4A is a side perspective view of the exemplary smoke unit for usewith embodiments of the cooking devices described herein;

FIG. 4B is a rear perspective view of the smoke unit of FIG. 4A;

FIG. 4C is a side cross-sectional view of the smoke unit of FIG. 4A;

FIG. 4D is a partial cross-sectional view of the smoke unit of FIG. 4A;

FIG. 4E is a side perspective view of a lid of the smoke unit of FIG.4A;

FIG. 4F is an exploded view of the smoke unit of FIG. 4A;

FIG. 5 is a schematic diagram illustrating components of the cookingdevice of FIG. 1A;

FIG. 6 illustrates a flow chart for controlling the speed of the fanwhen the cooking device 10 is operating in fan compensation mode,according to one or more embodiments described and illustrated herein;

FIG. 7 illustrates a graphical representation of values that can becalculated by the controller using a first transfer function, accordingto some embodiments described and illustrated herein;

FIG. 8 illustrates a three dimensional graphical representation ofvalues that can be calculated by the controller using a second transferfunction, according to some embodiments described and illustratedherein;

FIG. 9 depicts a two-dimensional graphical representation including onlythe TRIAC set point values and electric power values;

FIG. 10 depicts a set point included as part of an alternating current(AC) waveform;

FIG. 11 depicts a non-linear relationship between operating speeds ofthe fan blades based on variations in the set point of the TRIAC;

FIG. 12 depicts a substantially linear relationship between electricpower values and operating speeds;

FIG. 13A depicts a graphical representation that shows a relationshipbetween supply voltages and electric power values at various set points,according to some embodiments described and illustrated herein;

FIG. 13B depicts fitting lines that indicate relationships betweenelectric power values and supply voltages at various set point values;

FIG. 13C illustrates a graphical representation includes an intersectionpoint of various fitting lines and a plurality of additional supplyvoltage values and a plurality of additional electric power values;

FIG. 14 depicts a graphical representation that shows a relationshipbetween set points of the TRIAC and the electric power values at theseset points;

FIG. 15 depicts a graphical representation of a sigmoid function;

FIG. 16 depicts a graphical representation that includes a line thatfits the data used to generate the graphical representation of FIG. 15 ,according to some embodiments described and illustrated herein;

FIG. 17 depicts a graphical representation of an electric powerdelivered to an inductive load upon which the decaying value is appliedover a particular time frame, according to some embodiments describedand illustrated herein;

FIG. 18 depicts a graphical representation of the operating speed of theinductive load based on the gradual reduction of the electric powerdelivered to the inductive load, as illustrated in FIG. 17 ;

FIG. 19 is a block diagram of an exemplary computing system inaccordance with an illustrative implementation of the current subjectmatter.

It is noted that the drawings are not necessarily to scale. The drawingsare intended to depict only typical aspects of the subject matterdisclosed herein, and therefore should not be considered as limiting thescope of the disclosure.

DETAILED DESCRIPTION

Certain exemplary embodiments will now be described to provide anoverall understanding of the principles of the structure, function,manufacture, and use of the devices and methods disclosed herein. One ormore examples of these embodiments are illustrated in the accompanyingdrawings, and additional examples of specific system structures,functions, manufactures, uses, and related methods can be found in U.S.application Ser. Nos. 17/733,237, 17/663,582, 18/307,595, 18/307,583,and 18/079,781, each of which is incorporated by reference herein in itsentirety Those skilled in the art will understand that the devices andmethods specifically described herein and illustrated in theaccompanying drawings are non-limiting exemplary embodiments and thatthe scope of the present invention is defined solely by the claims. Thefeatures illustrated or described in connection with one exemplaryembodiment may be combined with the features of other embodiments. Suchmodifications and variations are intended to be included within thescope of the present invention.

Further, in the present disclosure, like-named components of theembodiments generally have similar features, and thus within aparticular embodiment each feature of each like-named component is notnecessarily fully elaborated upon. Additionally, to the extent thatlinear or circular dimensions are used in the description of thedisclosed systems, devices, and methods, such dimensions are notintended to limit the types of shapes that can be used in conjunctionwith such systems, devices, and methods. A person skilled in the artwill recognize that an equivalent to such linear and circular dimensionscan easily be determined for any geometric shape.

In general, methods and systems for open-loop ignition of a smoke unitfuel source are provided. The open-loop ignition process can determinean average rate of energy supplied to the igniter during a predeterminedperiod of time of activation of the igniter and during an initialignition operating mode of the igniter. The open-loop ignition processcan then determine an average temperature of a region proximate theigniter during the predetermined period of time adjust a maximum time ofactivation of the igniter when the igniter is operating in the initialignition operating mode during a subsequent period of time following thepredetermined period of time based on the determined average rate ofenergy and the determined average temperature. After the maximum time ofactivation has elapsed, the igniter can be deactivated.

In addition to describing methods and systems for open-loop ignition ofa smoke unit fuel source, the present disclosure also describes methodsand systems for controlling the delivery of power to inductive loads. Asstated above, devices that utilize inductive loads, e.g., shaded-polemotors, to control the operating speeds of fans disposed in thesedevices suffer from numerous drawbacks. The performance of shaded-polemotors are negatively impacted by supply voltage variations, a low powerfactor, and low initial torque during device activation.

The transfer function based power delivery system described hereinaddresses and overcomes these drawbacks. In particular, the system isimplemented by a controller of a cooking device and operates to receivedata representative of a supply voltage from a power source that isexternal to the controller. A power sensor that is communicativelycoupled to the controller can operate to detect the supply voltage androute data representative of the supply voltage to the controller. Thecontroller then accesses a target operating speed for the inductive loadthat is specific to the supply and implements a transfer function basedalgorithm to determine a set point value using the electric value. Inparticular, the controller then determines a set point value specific toa target power and the supply voltage that is delivered to the device inwhich the controller is disposed. The controller applies the set pointvalue to a TRIAC of the device and adjusts the operation of theinductive load to the target power based on the application of the setpoint value. The operation of the inductive load at the target powerensures that the inductive load operates at the target operating speed.

The use of the transfer function based algorithm, which includes one ormore transfer functions to control the operating speeds of motors,provides various benefits. Specifically, the use of transfer functionsimproves the amount of mechanical rotational energy (output consistency)generated by the shaded-pole motors and the accuracy with which theoperating speeds of these motors are modulated. The system describedherein also provide these devices with power compensation and regulationunder various conditions, e.g., during initiation (e.g., starting) of adevice from an inactive or “cold” state. Additionally, the use oftransfer functions enables efficient use of memory because thesetransfer functions can be approximated and solved using a set ofpolynomial expressions.

FIGS. 1-2 illustrate a cooking device 10 according to an embodiment andfor use in some implementations of the current subject matter. Thecooking device 10 can be used to cook food in a variety of cookingmodes, including conductive and convective modes (e.g., sauté, grill,bake, air fry, dehydrate, roast, broil, etc.). The cooking device 10includes a base 12 and a movable cover, such as a lid 14, movablycoupled to the base 12, such as via a hinge 16. Together, the base 12and the lid 14 can be referred to generally as a housing and can definean interior cooking chamber 20 that is sized to receive a variety offood products and/or food containers (e.g., a baking tray, a rack,etc.). A seal 15 can be located at a perimeter of the base 12 and/or thelid 14 to assist in sealing the interior cooking chamber 20 at the pointof connection between the base 12 and the lid 14 when the lid 14 is in aclosed position. The seal 15 can generally operate like a gasket and canbe any material capable of operating as a seal, as would be known by aperson skilled in the art. For example, the seal 15 can be rubber,plastic, fiberglass, metal, or any other material.

The base 12 can include a cooking surface 18 upon which a food productcan be placed during an operating procedure of the cooking device 10,such as a grill or griddle surface, cooking stone (e.g., pizza stone,and the like), a wire rack, or another type of platform. The cookingdevice 10 can include at least one heating element disposed in the lid14, the base 12, and/or the interior cooking chamber 20 that isconfigured to heat the cooking surface 18, the interior cooking chamber20 and/or the food product through conduction, convection, radiation, ora combination thereof In some variations, the cooking device 10 caninclude a first heating element 22A disposed beneath the cooking surface18 and a second heating element 22B disposed in the lid 14. The cookingdevice 10 can also include at least one vent 24 located within the lid14 and/or the base 12 to allow airflow to exit the interior cookingchamber 20. The vent 24 can be seen at least in FIG. 2 located on a rearof the cooking device 10. As a result of the seal 15 located around aperimeter of the base 12 and/or the lid 14, the vent 24 can be theprimary (or the only) airflow exit for the interior cooking chamber 20.Accordingly, the size of the vent 24 can proportionally drive airflowthrough the cooking device 10.

The cooking device 10 can also include a fan 30, which can be operatedto circulate air within the interior cooking chamber 20 during a varietyof cooking modes. The fan 30 can be located within the interior cookingchamber 20, and can be coupled to the lid 14, the base 12, or any otherportion of the cooking device 10. For example, in some embodiments, thefan 30 is located on an upper region of the interior cooking chamber 20and can be configured to rotate about a vertical axis. A motor 32capable of driving the fan 30 can be located within a motor housing 34externally of the interior cooking chamber 20. In some variations, thefan 30 can be located external to the interior cooking chamber 20 andcan be in fluid communication with the interior cooking chamber 20through an air pathway, such as a ventilation system or the like.

The cooking device can include a user interface 40 located on anexternal portion of the cooking device 10, such as on a front face ofthe base 12, as seen, for example, in FIG. 1 . The user interface 40 caninclude a screen 42 and a variety of inputs 44 with which a user canselect various parameters for a cooking and/or a smoke process for afood product. The user interface 40 can include a variety ofpre-programmed operating modes. These cooking modes can includeconductive, convective, and radiative heating modes, such as grilling,baking, air frying, dehydrating, broiling, and other known cookingmodes. Further, these cooking modes can combined with smoke generated bya smoke unit 50 as explained in further detail below. Smoke can beintroduced from the smoke unit, and can include low-and-slow modes toimpart smoke over a longer period of time and perfume smoke to impartsmoke flavor over a short period of time. Further, smoke can be impartedonto a food product independent of a cooking mode, such that the foodproduct may be imparted with smoke flavor without being cooked. Any ofthe listed operations can be used in combination with one another, bothin succession or at the same time.

The cooking device 10 can also employ a smoke unit 50 coupled to thecooking device 10 to impart smoke flavor onto a food product in anymode. The smoke unit 50 is described in further detail below and withrespect to FIGS. 4A-4F. The smoke unit 50 can be coupled internally orexternally to the cooking device 10, such as to the base 12, the lid 14,or anywhere else on the cooking device. The smoke unit 50 can receive afuel source, such as wood pellets, and can ignite the pellets using aheating element to generate smoke to impart flavor onto a food productcontained within the interior cooking chamber. The generation of smokecan occur during a cooking mode to impart smoke flavors. Further, thecooking device 10 can employ the smoke unit 50 independent of a cookingmode in order to impart smoke flavor to a food product without cookingthe food product. The smoke unit 50 can also include an intake locatedon an exterior thereof, which can provide the cooking device 10 with asource of new air to feed a smoke generation process and allow for airto circulate within the interior cooking chamber 20. The intake can beintentionally and deliberately sized to correspond to a size of the vent24 located on the lid 14 and/or the base 12 of the cooking device suchthat the amount of airflow exiting the interior hollow chamber isapproximately equal to the amount of airflow entering the intake.

The cooking device 10 can also employ a smoke channel to introduce smokegenerated by the smoke unit into the interior cooking chamber. The smokechannel can provide a pathway through which generated smoke can bedrawn, by operation of the fan, into the interior cooking chamber inorder to impart smoke flavor onto a food product. Further, the smokechannel can also form part of an airflow pathway that begins with theintake of the smoke unit 50 and ends with the vent 24. The smoke channelcan come in a variety of forms, as will be discussed below.

FIGS. 3A and 3B depict another embodiment of a cooking device 10′. Theillustrated cooking device 10′ can be generally similar to cookingdevice 10, and for brevity, similar components will not be describedagain. For example, the cooking device 10′ can generally include ahousing 12′, a smoke unit 50′, a fan 30′, and a user interface 40′.However, in this embodiment the cooking device 10′ includes a movablecover that is in the form of a door 14′ that can be pivoted open on thefront of the cooking device. Further, an exemplary difference betweenthe cooking device 10′ and the cooking device 10 is the location of thefan 30′ on the cooking device 10′. As shown in FIG. 3B, the fan 30′ islocated on a rear wall 12A′ of the interior cooking chamber 20′, ratherthan on a ceiling or upper region of the interior cooking chamber 20′.Generally, the fan 30′ can be located on a wall of the interior cookingchamber 20′ opposite the front and the movable door 14′. In thisarrangement, the fan 30′ can rotate about a horizontal axis, but the fan30′ generally operates in a similar manner as the fan 30. The smokechannel 100 can be seen in the right side of the housing 12′, and thesmoke channel 100 can be at least partially defined by the housing 12′,similar to the form of the smoke channel 100. The smoke channel 100 canlead from the smoke unit 50′ at a first end 102 thereof to the fan 30′at a second end 104 thereof. Despite the difference in arrangementbetween the cooking device 10 and the cooking device 10′, the principleof operation of the smoke channel 100 is generally the same in eachdevice. Accordingly, although reference is made herein to the cookingdevice 10, descriptions are equally applicable to the cooking device10′.

As referenced above, FIGS. 4A-4F illustrate an exemplary embodiment of asmoke unit, such as the smoke unit 50 described above, that can be usedin some implementations of the current subject matter. Generally, thesmoke unit 50 is configured to generate smoke for use in a cookingoperation. The smoke unit 50 can be mounted to an exterior surface ofthe movable cover, such as lid 14, and is configured to be in fluidcommunication with the interior cooking chamber 20 via a lid aperture 18d. While the smoke unit 50 is described herein as being mounted tocomponents of the cooking device 10 and the cooking device 10′, in someembodiments, the smoke unit 50 can be coupled to additional types ofcooking devices, such as a propane grill configured to cook food with apropane-fueled heat source. For example, in some embodiments, the smokeunit 50 can be similarly mounted to an exterior surface of such apropane grill and configured to be in fluid communication with aninterior cooking chamber of the propane grill, in which food is placedfor cooking, via an aperture formed in the exterior surface.

The smoke unit 50 can include a smoke unit housing 52 having a generallyrectangular configuration with top and bottom surfaces 52 a, 52 b, andfour sides—narrower left and right sides 52 c, 52 d, and wider front andrear sides 52 e, 52 f—that together form an interior cavity 54. As shownin FIGS. 4A-4F, the front side 52 e, proximate the base 12, is formed tofit a contour of the outer surface of the lid 14, and therefore may beshorter than the rear side 52 f. The rear side 52 f, opposite the frontside 52 e, may include a first air intake 56 a disposed at a lowerregion to allow air into the interior cavity 54. The top surface 52 aincludes a lid 58 hinged to the smoke housing 52 that leads to theinterior cavity 54. In some embodiments, the lid 58 is biased to aclosed position via a spring 58 a with enough force to preventaccidental opening, or to prevent excess air from seeping into theinterior cavity 54. The interior cavity 54 is sized to receive aninsertable removable fuel box assembly 60 therein. In some embodiments,the force exerted by spring 58 a is large enough to prevent the fuel boxassembly 60 from sliding out of the smoke unit housing 52 when the lid14 is in an open position.

The fuel box assembly 60 can be configured to receive and retain fuelfor use during a cooking operation, and the fuel box assembly 60 canalso catch and hold ash generated by combustion of the fuel. The fuelbox assembly 60, seen within the smoke unit housing 52 in FIG. 4C andremoved from the smoke unit housing 52 in FIG. 4F, includes left andright sidewalls 60 a, 60 b, and front and rear sidewalls 60 c, 60 d,which are wider than the left and right sidewalls 60 a, 60 b similar tothe smoke unit housing 52. The fuel box assembly 60 also includes a topsurface 60 e and a bottom surface 60 f which extend between thesidewalls 60 a-d at respective top and bottom ends. The particular shapeand arrangement of the fuel box assembly 60 can vary in dimension, andcertain features can be rounded or generally altered from what isdepicted. The front sidewall 60 c, disposed proximate the housing 52, isshown covered by a mesh 64 with a plurality of small apertures 62 adisposed thereon. At an upper region of the front sidewall, beyond themesh, the smoke unit further includes a large aperture 62 b. Theparticular amount and arrangement of apertures 62 a, 62 b can vary innumber, arrangement, and/or dimension. The rear sidewall of the fuel boxassembly 60 is substantially solid, except for at a lower region, whichcan contain a second air intake 56 b that aligns with the first airintake 56 a located on the rear sidewall of the smoke unit housing 52.The first and second air intakes 56 a, 56 b define a portion of anairflow path through the cooking device 10.

The fuel box assembly 60 is further configured to be placed within thesmoke unit housing 52 to substantially conform with the left, right, andrear sides. A region near the front side of the smoke unit housing 52proximate the upper lid portion can be larger than a region occupied bythe fuel box assembly 60, and is thus not filled by the fuel boxassembly 60 when the fuel box assembly 60 is inserted into the smokeunit housing 52. As shown in FIGS. 4A-4F, this region can contain anigniter 66, such as a wire heating element, that is configured to heatfuel contained in the fuel box assembly 60 through the smaller apertures62 a of the mesh 64 on the front fuel box assembly sidewall 60 e. Invarious embodiments, the igniter 66 can take on various forms, such as,for example, an electrical tubular heating element having a firstterminal end at one end of the heating element and a second terminal endat an opposite end of the heating element, or a sparking device. Whensmoke generation is required for a cooking operation, the igniter 66 canbe powered on to ignite fuel contained in the fuel box assembly 60.

As further shown in FIGS. 4A-4F, the fuel box assembly 60 has aninterior space. This interior space is divided into two regions, anupper region in the form of a pellet box 68 that is configured toreceive and hold fuel for use during a smoke generation process, and alower region in the form of an ash catcher 70 that is configured toreceive and store ash created during a smoke generation process. Thepellet box 68 and the ash catcher 70 are shown in the illustratedembodiment as being separated by a mesh divider 72. The mesh divider 72includes apertures which are sized to be large enough to allow for ashto fall from the pellet box 68 to the ash catcher 70 during a smokegeneration process, while also being small enough to prevent fuel frompassing through the mesh divider 72. The ash catcher 70 is furtherconfigured to retain ash generated by the fuel box assembly 60, suchthat removal of the fuel box assembly 60 from the smoke unit housing 52will also remove ash from the smoke unit housing 52 to facilitatedisposal and prevent ash spillage. A person skilled in the art willappreciate that other techniques can be used to separate ash from thefuel.

In some embodiments, and as depicted in the FIGS. 4A-4F, the smoke unit50 can include a temperature sensor 74 disposed proximate to the igniter66. The temperature sensor 74 can take on any suitable form, and, forexample, may be one of a thermocouple, a resistance temperature detector(RTD), a thermistor, and a semiconductor based integrated circuit.However, any form of sensor capable of measuring temperature can beused. The temperature sensor 74 is configured to measure a temperatureof the interior of the fuel box assembly 60 during smoke processes andnon-smoke processes.

The smoke unit interior 54, including the interior of both the smokeunit housing 52 and the fuel box assembly 60, are in fluid communicationwith the interior cooking chamber 20. As mentioned previously, and asshown especially in FIG. 4C, the front sidewall of the smoke unit 50,above the region containing the igniter 66, contains a large aperture 62b. The large aperture 62 b defines part of the airflow pathway, joiningthe smoke unit 50 interior with the interior cooking chamber 20.Covering the large aperture 62 b, as depicted in FIGS. 4A-4C, is abaffle 80 disposed in the airflow path. When the smoke unit 50 iscoupled to the cooking device 10 at the lid aperture 18 d, the baffle 80passes through the lid aperture 18 d and is thereby positioned withinthe interior cooking chamber 20.

In the embodiment shown in FIGS. 4A-4F, the baffle 80 is a tunnel baffle82. The tunnel baffle 82 can include a cover 82 c spanning the largeaperture 62 b that is oriented horizontally to align with a direction ofairflow in the interior cooking chamber 20. The cover 82 c can includeopenings at each end thereof such that, in relation to airflow throughthe interior cooking chamber 20, one opening is an upstream opening 82 aand the other opening is a downstream opening 82 b.

As schematically illustrated in FIG. 5 and as referenced above, thecooking device 10 can include a controller 100 that is in operablecommunication with one or more of the components described above (e.g.,the user interface 40, the fan 30, the temperature sensor 74, etc.). Asshown, the controller 100 can include at least one processor 101 and amemory 102 storing instructions which, when executed by the processor101, can cause the at least one data processor to perform one or more ofthe operations described elsewhere herein. The controller 100 can alsoinclude an input/output (I/O) interface 103 that enables the processor101 to receive commands and/or data from other components of the cookingdevice 10 for use in performing the operations.

As shown in FIG. 5 , the cooking device 10 can also include a powersupply 110 that is configured to supply power to the igniter 66 (inaddition to other components of the cooking device 10 requiring power tooperate). The power supply 110 can be in operable communication with thecontroller 100 and the igniter 66. As such, the power supply 110 can beconfigured to receive commands from the controller 110 (provided via theI/O interface 103) that cause the power supply 110 to provide electricalpower to the igniter 66 to thereby cause the igniter 66 to activate. Insome embodiments, the power delivered to the igniter 66 can vary basedon the commands received from the controller 65. For example, the leveland/or duration of power supplied to the igniter 66 can vary over agiven period of time based on power delivery instructions characterizedby the commands received from the controller 100. As a result, the leveland/or duration of heat being supplied to the fuel contained within thesmoke unit 50 can vary over the given period of time based on thecommands received from the controller 100.

In some embodiments, the activation of the igniter 66 can occur when anignition mode is selected via the user interface 40. When this occurs,the controller 100 can cause the power supply 110 to supply full powerto the igniter 66.

In some embodiments, the controller 100 can be configured to receivedata characterizing a plurality of measurements of a rate of energy(e.g., power, etc.) that is supplied to the igniter 66 of the smoke unit50 by the power supply 110 and a plurality of measurements of atemperature of a region proximate the igniter 66 as acquired by thetemperature sensor 74. Each of the plurality of measurements can beacquired at regular intervals during a predetermined period of time(e.g., every second over a 30 second period of time). In someembodiments, the predetermined period of time can be a period of timeduring which the igniter 66 is activated and/or during an initialoperating mode of the igniter 66 (e.g., an operating mode during whichthe igniter 66 is used for the first time since the cooking device hasbeen powered on). In some embodiments, each of the plurality ofmeasurements of the rate of energy can be acquired with a power sensor(not shown) that is configured to measure the rate of energy supplied tothe igniter 66 by the power supply 110.

In some embodiments, each of the plurality of measurements of the rateof energy supplied to the igniter 66 can be derived from a measurementof voltage applied to the igniter 66 and a measurement of a resistanceof the igniter 66. For example, in some embodiments, measurements of thevoltage applied to the igniter 66 can be acquired with a voltage sensor(not shown) that is configured to acquire a value of the voltage, andmeasurements of the resistance of the igniter 66 can be acquired with aresistance sensor (not shown) that is configured to acquire an amount ofresistance of the igniter 66. Each of the plurality of measurements ofthe rate of energy supplied to the igniter 66 can be derived using theequation P=V²/R, where P is the measurement of the rate of energysupplied to the igniter 66, V is the measured voltage, and R is themeasured resistance. In some embodiments, each of the plurality ofmeasurements of the rate of energy supplied to the igniter 66 can bederived using an assumed value of resistance of the igniter 66 in lieuof or in addition to using a measured value of resistance.

In some embodiments, each of the plurality of measurements of the rateof energy supplied to the igniter 66 can be derived from a measurementof current passing through the igniter 66. For example, in someembodiments, measurements of the current passing through the igniter 66can be acquired with a current sensor (not pictured) that is configuredto acquire a value of the current. Each of the plurality of measurementsof the rate of energy supplied to the igniter 66 can be derived usingthe equation P=I²*R, where P is the measurement of the rate of energysupplied to the igniter 66, I is the measured current, and R is themeasured resistance. In some embodiments, each of the plurality ofmeasurements of the rate of energy supplied to the igniter 66 can bederived using an assumed value of resistance of the igniter 66 in lieuof or in addition to using a measured value of resistance.

In some embodiments, each of the plurality of measurements of the rateof energy supplied to the igniter 66 can be derived from the measurementof current passing through the igniter 66 and the measurement of voltageapplied to the igniter 66. For example, current and voltage measurementscan be acquired using the current and voltage sensors described above,respectively, and each of the plurality of measurements of the rate ofenergy supplied to the igniter 66 can be derived using the equationP=I*V, where P is the measurement of the rate of energy supplied to theigniter 66, I is the measured current, and V is the measured voltage.

In some embodiments, at the conclusion of the predetermined period oftime, the controller 100 can be configured to determine an average rateof energy supplied to the igniter 66 during the predetermined period oftime. For example, the controller 100 can calculate an average of eachof the received plurality of measurements of the rate of energy suppliedto the igniter 66 during the predetermined period of time to determinean average rate of energy supplied to the igniter 66 during thepredetermined period of time. Similarly, in some embodiments, thecontroller 100 can be configured to determine an average temperature ofthe region proximate the igniter 66 during the predetermined period oftime. For example, the controller 100 can calculate, using each of thereceived plurality of measurements of the temperature of the regionproximate the igniter 66, an average value of the temperature of theregion proximate the igniter 66.

In some embodiments, the controller 100 can monitor the length of timeduring which the igniter 66 is activated. As such, the controller 100can be configured to determine, based on the determined average rate ofenergy supplied to the igniter 66 and the determined average temperatureof the region proximate the igniter 66, a maximum time of activation ofthe igniter when the igniter is operating in the initial ignitionoperating mode and during a subsequent period of time that follows thepredetermined period of time. The controller 100 can be configured toadjust the maximum time of activation of the igniter 66 when the igniter66 is operating in the initial ignition operating mode and during thesubsequent period of time based on a variety of factors. For example,the controller 100 can adjust the maximum time of activation based onthe determined average rate of energy and/or the determined averagetemperature. For example, the maximum time of activation can bedetermined using a weighted average algorithm in which the determinedaverage temperature of the region proximate the igniter 66 and/or thedetermined average rate of energy supplied to the igniter 66 areprovided as variables that are multiplied by negative value weightfactors. As such, the determined maximum time of activation can varyinversely with the average temperature of the region proximate theigniter 66 and/or the determined average rate of energy supplied to theigniter 66.

In some embodiments, the maximum time of activation can be determinedbased on an average amount of voltage applied to the igniter 66 duringthe predetermined period of time. For example, the controller 100 cancalculate an average of each of the received plurality of measurementsof the voltage applied to the igniter 66 during the predetermined periodof time to determine the average amount of voltage supplied to theigniter 66 during the predetermined period of time. The determinedaverage amount of voltage applied to the igniter 66 can be used in lieuof or in addition to the determined average rate of energy supplied tothe igniter 66 in determining the maximum time of activation in themanner described above. In some embodiments, the average amount ofvoltage applied to the igniter 66 can be used in lieu of the determinedaverage amount of voltage supplied to the igniter 66 when the resistanceof one or more heating elements in the cooking device 10 (e.g., igniter66) is assumed to be the same value.

In some embodiments, the controller 100 can be configured to adjust themaximum time of activation of the igniter 66 based on an operating modeof the smoke unit 50. For example, the controller 100 can use a firstalgorithm for determining the maximum time of activation of the igniter66 when the smoke unit 50 is being used in a smoker operating mode) (inwhich the smoke generator outputs smoke for an extended duration of time(e.g., a relatively long portion of, or all of, the time during whichthe food is cooked using the cooking device 10)) and/or a secondalgorithm for determining the maximum time of activation of the igniter66 when the smoke unit 50 is being used in an infusion operating mode(in which the smoke generator outputs a limited-duration burst of smokeon an on-demand basis (e.g., a relatively short portion of the timeduring which the food is cooked with the cooking device 10)). The firstalgorithm and/or the second algorithm can be substantially similar tothe weighted average algorithm described above (e.g., the determinedaverage temperature of the region proximate the igniter 66 and/or thedetermined average rate of energy supplied to the igniter 66 areprovided as variables to the first and second algorithms that aremultiplied by negative value weight factors). However, the magnitudes ofthe negative value weight factors for each of the first algorithm andthe second algorithm can differ based on the operating mode of the smokeunit 50.

In some embodiments, the controller 100 can be configured to adjust(e.g., increase or decrease) an amount of power delivered to the fan 30during the initial ignition operating mode. In some embodiments, thecontroller 100 can receive, from a temperature sensor (not shown)located in the cooking chamber 20, data characterizing the temperatureof the cooking chamber 20. The controller 100 can determine a differencebetween the temperature of the cooking chamber 20 and the temperature ofthe region proximate the igniter 66 characterized by one or more of theabove-described plurality of measurements, and the controller 100 candetermine whether the determined difference is less than or equal to apredetermined temperature difference threshold value (e.g., 6 degreesCelsius). Additionally, the controller 100 can be configured todetermine whether the temperature of the region proximate the igniter 66and the temperature of the cooking chamber 20 are each less than apredetermined temperature threshold. When the difference between thetemperature of the cooking chamber 20 and the temperature of the regionproximate the igniter 66 is less than or equal to the predeterminedtemperature difference threshold value, and when the temperature of theregion proximate the igniter 66 and the temperature of the cookingchamber 20 are both less than a predetermined temperature threshold, thecooking device 10 is determined to be in a “cold state” at the beginningof the ignition process (e.g., a state in which the cooking device 10has not been recently used and, as such, is not at a temperature that isclose to the normal operating temperature of the cooking device 10).

As such, when the controller 100 determines that the cooking device 10is in a “cold state,” the controller 100 can operate the cooking device10 in a fan compensation mode in which the amount of power delivered tothe fan 30 is adjusted. The fan compensation mode can allow foroptimized ignition of the fuel located in the smoke unit 50 when thecooking device 10 is in the “cold state.” For example, in someembodiments, the controller 100 can cause an adjusted (e.g., increasedor decreased) amount of power to be delivered to the fan 30 in order tocompensate for internal friction that is present within the motor of thefan 30 when the cooking device is determined to be in the cold state(by, for example, determining that the temperature of the cookingchamber 20 is less than a predetermined threshold) and thereby maintainthe operating speed of the fan at a rotational speed that allows for theoptimized ignition of the fuel located in the smoke unit 50. As thetemperature of the cooking chamber 20 increases, the internal frictionabates and as such the controller 100 can deactivate the fancompensation mode in response to determining that the temperature of thecooking chamber 20 exceeds a predetermined threshold. For example, oncethe temperature of the cooking chamber 20 has increased such that thecooking device 10 is no longer in the cold state, the controller 100 candeactivate the fan compensation mode and adjust (e.g., increase ordecrease) the amount of power delivered to the fan and thereby maintainthe operating speed of the fan at the rotational speed that allows forthe optimized ignition of the fuel located in the smoke unit 50.Additionally, in some embodiments, when the controller 100 is operatingthe cooking device 10 in the fan compensation mode, the controller 100can monitor a level of voltage generated by the power supply 110 anddetermine whether the level of voltage is less than a predeterminedthreshold. In response to determining that the level of voltagegenerated by the power supply 110 is less than the predeterminedthreshold, the controller 100 can cause an increased amount of power tobe delivered to the fan 30 to compensate for the level of voltagegenerated by the power supply 110 being less than the threshold andthereby maintain the operating speed of the fan at the rotational speedthat allows for the optimized ignition of the fuel located in the smokeunit 50. After each of the operations of the fan compensation mode haveconcluded, the controller 100 can adjust (e.g., increase or decrease)the amount of power delivered to the fan 30 such that the operatingspeed of the fan 30 is adjusted to a preset value for ignition of thefuel within the smoke unit 50. After the operating speed of the fan 30has been adjusted to the preset value, the controller 110 can continueto operate in the ignition mode until the maximum time of activation haselapsed.

In some embodiments, such as those where the fan compensation mode isnot active or enabled, after the controller has determined the maximumtime of activation and during the above-described subsequent period oftime, the controller 100 can cause a maximum amount of power to besupplied to the fan 30, such that the fan 30 operates at full power,until a predetermined portion of the subsequent period of time haselapsed (e.g., 120 seconds). Once the predetermined portion has elapsed,the controller 100 can adjust the amount of power delivered to the fansuch that the operating speed of the fan 30 is adjusted to the presetvalue described above. And, similar to the above-describedfunctionality, after the operating speed of the fan 30 has been adjustedto the preset value, the controller 110 can continue to operate in theignition mode until the maximum time of activation has elapsed.

The cooking device 100 also includes a power sensor 76 that iscommunicatively and operably coupled to the controller 100 and the powersupply 110. In operation, the power supply 110 can receive a steadystream of voltage (“supply voltage”) from an external power source suchas an electrical outlet. For example, one end of a three pronged cordcan be connected to the external power source and the other end may bedirectly connected to the power supply 110. Thereafter, when the cookingdevice 10 is activated (e.g., turned on), voltage in a range of 110 V to120 V can be consistently delivered to the power supply 110 by theexternal power source. The power supply 110 uses the received voltage todrive current to several components of the cooking device 10, namely thecontroller 100. The driving or movement of the current by the receivedvoltage results in the generation of electrical power, which operatesvarious components of the cooking device 10.

In some embodiments, the power sensor 76 detects, substantially in realtime, a supply voltage that is received by the power supply 110 andcommunicates data representative of the supply voltage to the controller100. The controller 100 stores this data in memory 102. In someembodiments, the power sensor 76 can be configured to detect the supplyvoltage at fixed time intervals, at a predefined time, and so forth. Thecontroller 100 utilizes the data representative of the supply voltage toperform calculations using, e.g., a transfer function based algorithmthat utilizes one or more transfer functions. Details regarding theimplementation of the transfer functions will be described later on inthis disclosure. Broadly speaking, the controller 100 receives electricpower from the power supply 110 and implements one or more transferfunctions to deliver a precise amount of electric power to the fan 30.Controlling the amount of electrical power delivered to the fan 30enables control over the operating speed of the fan, namely the rate ofrotation of the blades of the fan 30.

FIG. 5 also schematically illustrates various components of the fan 30,namely a TRIAC 78, an inductive load 80, and fan blades 82. The TRIAC78, a component that is in operable communication with the controller100 and the inductive load 80, is a three-pinned electronic circuit usedto control an amount of current that flows to a component, and byextension, the amount of power delivered to the component. TRIACs areused as dimmer switches for lighting components, output controllers forelectric heaters, and as components that control the operating speed ofmotors. One such motor is a shaded-pole motor, which utilizes a magneticfield to convert electrical current into mechanical rotational energy.The shaded-pole motor, one example of the inductive load 80, is inoperable communication with the TRIAC 78 and the fan blades 82. When thecooking device operates in fan compensation mode, the controller 100 canadjust the operating speed of the fan blades 82 by controlling theamount of electric power delivered to the shaded-pole motor.

For example, to increase the operating speed of the fan blades 82relative to a current operating speed, the controller 100 can increasean amount of electric power delivered to the inductive load 80. Deliveryof a higher electric power causes the inductive load 80 (e.g., theshaded-pole motor) to generate a higher amount of mechanical rotationalenergy which, when delivered by the inductive load 80 to the fan blades82, increases the operating speed (i.e. rotational speed) of the fanblades 82. Conversely, to decrease the operating speed of the fan blades82, the controller 100 can decrease an amount of power delivered toinductive load 80. A lower electric power causes the inductive load 80(e.g., the shaded-pole motor) to generate a lower amount of mechanicalrotational energy which, when delivered by the inductive load 80 to thefan blades 82, decreases the operating speed (i.e. rotational speed) ofthe fan blades 82 relative to the current operating speed.

FIG. 6 illustrates a flow chart 600 for controlling the speed of the fan30 when the cooking device 10 is operating in fan compensation mode,according to one or more embodiments described and illustrated herein.It is noted that FIGS. 7-10 will be discussed interchangeably with thediscussion of FIG. 6 .

At block 602, the controller 100 can receive data representative of anelectrical value. The electrical value can be a supply voltage, acurrent, or a power. In aspects, a supply voltage from a power sourcethat is external to the controller 100 may be received. For example, asdescribed above with respect to FIG. 5 , the power sensor 76 can detectthe voltage supplied to the power supply 110 by an external power source(e.g., an electrical outlet) and communicate data representative of thedetected voltage to the controller 100. The controller 100 then storesthe data in the memory 102 of the controller 100. While the externalpower source is capable of supplying 120 V, the supply voltage typicallyreceived from the external power source can be in a range from 104 V to120 V because there is a drop in the supply voltage from 120 V to 110 V(or 104 V) when the cooking device 10 is activated (e.g., turned on). Inaspects, the voltage supplied by the external power source to the powersupply 110 can be in the range of 110 V to 120 V and the drop in voltage(i.e. voltage sagging) can be in a range from 2 V to 6 V. Such a voltagedrop or voltage sag occurs because the external power source can beconnected to a high power load such as, e.g., the inductive load 80.

At block 604, the controller 100 can access, from the memory 102, atarget value (e.g., a target speed) for the inductive load 80 at thesupply voltage (electrical value) that is delivered to the cookingdevice 10. For example, during the design and manufacture of the cookingdevice 10, a particular operating speed of the fan blades 82 can bepreprogrammed in the memory 102. As such, the controller 100 operates tofacilitate deliver of a requisite amount of electric power to theinductive load 80 to ensure that the fan blades 82 consistently operateat this preprogrammed operating speed. In fact, one of the purposes ofthe fan compensation mode is to ensure that the fan blades 82consistently operate at the preprogrammed operating speed. Thepreprogrammed operating speed can be 1000 RPM. In other embodiments, thepreprogrammed operating speed can be an operating speed range, e.g., 800revolutions per minute (RPM), 900 RPM, 1000 RPM, or an operating speedrange of 500-700 RPM.

In some embodiments, the controller 100 initiates operation of thecooking device 10 in the fan compensation mode, automatically andwithout user intervention, upon determining that the fan blades 82 failto operate at the preprogrammed operating speed, e.g., 1000 RPM. One waythat the controller 100 can determine the operating speed of the fanblades 82 is by receiving data from a sensor that is disposed in closeproximity with or directly on the fan blades 82. In operation, thesensor can detect, substantially in real time, the rotational speed ofthe fan blades 82 and communicate data representative of the rotationalspeed to the controller 100. The controller 100 can then compare therotational speed with the operating speed of the fan blades 82 that waspreprogrammed in the memory 102 to determine whether the fan blades 82are operating at the preprogrammed operating speed. Such sensors,however, are inaccurate, cost prohibitive, and difficult to install.

Additionally, conventional technologies suffer from excess costs becausethe controllers used in conventional technologies typically need anadditional pin in order to communicate directly with these expensive andinaccurate sensors. The need for such separate hardware interrupts theoperation of the timers on these controllers, which are configured tomeasure the operating speeds of motors connected to these timers. Due tothese interruptions, the controllers used in conventional technologiesmay be unable to measure the operating speeds of various components(e.g., motors) without reducing various time critical processes of thesecontrollers.

The methods and techniques described herein, namely the transferfunction based power delivery system of the present disclosure, addressand overcome the above described deficiencies. In particular, thetransfer function based power delivery system utilizes one or moretransfer functions in conjunction with temperature data and electricpower data to control operating speed of the fan blades 82, therebybypassing the need for the installation of sensors directly on or inclose proximity of the fan blades 82. For example, the controller 100can receive temperature data from the temperature sensor 74, electricpower data from the power sensor 76, and implement one or more transferfunctions using the electric power data to determine whether the fanblades 82 are rotating at a speed that matches the preprogrammedoperating speed.

If the rotating speed of the fan blades 82 is less than thepreprogrammed operating speed, the controller 100 can implement one ormore transfer functions to enable the supply of a particular amount ofelectric power to the inductive load 80, which in turn will generate andsupply a particular amount of mechanical power to the fan blades 82 toensure that the fan blade rotational speed matches the preprogrammedoperating speed. Similarly, if the rotating speed of the fan blades 82is more than the preprogrammed operating speed, the controller 100 willuse one or more transfer functions to supply another amount of electricpower to the inductive load 80, which in turn will generate and supplyanother amount of mechanical power to the fan blades to ensure that thefan blade rotational speed matches the preprogrammed speed.

At block 606, the controller 100 can implement a transfer function basedalgorithm for determining a set point value using the electrical valueof block 602. The implementation of the transfer function basedalgorithm can involve the processing of one or more transfer functions.In particular, the processing can involve determining, using a firsttransfer function, a target power for operating the inductive load 80 atthe target value (e.g., target speed). The target speed corresponds thepreprogrammed operating speed of the fan blades 82 described above withrespect to block 604. In some embodiments, the controller 100 can accessthe preprogrammed operating speed stored in the memory 102 and implementa transfer function (e.g., the first transfer function) to determine anamount of electric power that has to be delivered to the inductive load80. As stated above, the delivery of this electric power to theinductive load 80 causes the fan blades 82 to operate at thepreprogrammed operating speed. It is noted that the target speed is onlyone example of the target value. In embodiments, the target value cancorrespond to aspects other than speed.

FIG. 7 illustrates a graphical representation 700 of values that can becalculated by the controller 100 using the first transfer function,according to some embodiments described and illustrated herein. Thegraphical representation 700 includes an x-axis 702 and a y-axis 704.The values on the x-axis 702 correspond to electric power delivered tothe inductive load 80 at various time periods during the operation ofthe cooking device 10, and the values on the y-axis 704 correspond tovarious operating speeds of the fan blades 82 at various time periodsduring the operation of the cooking device 10. As illustrated, theelectric power values on the x-axis 702 range from 0 to 60 W and theoperating speeds on the y-axis 704 range from 0 to 4000 RPM.

The controller 100, upon accessing the target speed for the inductiveload at the supply voltage received from the external power source(e.g., 104 V to 120 V), accesses and implements a first transferfunction stored in the memory 102. In particular, the controller 100inputs the target speed that is preprogrammed into the memory 102 duringthe design and manufacture of the cooking device 102, e.g., an operatingspeed of 1000 RPM, into the first transfer function, and determines acorresponding electric power value as an output of the first transferfunction. The determined electric power value can then be delivered tothe inductive load 80 to control operation of the fan blades 82 toensure that the fan blades 82 operate at the target speed (i.e.preprogrammed operating speed).

For example, the controller 100 can access the target speed of 1000 RPMfrom the memory 102 and determine, using the first transfer function,that the corresponding electric power needed to generate this targetspeed is in the range of 19 Watts to 20 Watts. The controller 100 thenoperates to deliver the electric power of 19-20 Watts to the inductiveload 80 via the TRIAC 78. The controller 100 enables the delivery of19-20 Watts of electric power by selecting a particular setting on theTRIAC. Determining this setting requires the use of a second transferfunction, as described in greater detail below.

The graphical representation 700 depicts a line 706 that accuratelyapproximates a plurality of operating speeds of the inductive load 80(ranging from 0 to 4000 RPM) for a plurality of electric power values(ranging from 0 to 60 Watts) given a particular supply voltage, e.g.,the supply voltage in the range of approximately 104 V to 120 V. Asillustrated, the relationship between a particular electric power valueand a corresponding operating speed is substantially linear, asindicated by points 708, 710, 712, 714, and 716.

Further, the implementing of the transfer function based algorithm caninvolve the processing of a second transfer function. In particular, theprocessing of the second transfer function enables the determination ofa set point value (e.g., a setting) specific to the target power and thesupply voltage (e.g., 104 V to 110 V). After determining the targetpower for operating the fan blades 82 at a target speed, as describedabove with respect to blocks 604 and 606 above, the controller 100 caninput the values of the target power at the given target speed and thesupply voltage received from the external power supply into the secondtransfer function and determine a set point value for the TRIAC. The setpoint value corresponds to a setting in the TRIAC that enables thedelivery of the target power to the inductive load 80, which thengenerates mechanical rotational energy that is delivered to the fanblades 82 to rotate at the preprogrammed operating speed.

FIG. 8 illustrates a three dimensional graphical representation 800 ofvalues that can be calculated by the controller 100 using the secondtransfer function, according to some embodiments described andillustrated herein. In particular, the three-dimensional graphicalrepresentation 800 includes an x-axis 802 corresponding to TRIAC setpoint values (also referred to as Phase Angle Target (or PAT) values), ay-axis 804 corresponding to supply voltages, and a z-axis 806 thatcorresponds to electric power values. The graphical representation alsodepicts a curve 808 that captures the relationship between supplyvoltages, electric power values, and set point values.

As described above, the controller 100, having determined a target powervalue and the supply voltage, implements the second transfer functionand determines a set point for the TRIAC that is specific to the targetpower and the supply voltage. The values that can be determined usingthe second transfer function are shown in the curve 808 of the threedimensional graphical representation 800. For example, for a supplyvoltage of 220 V and a target power of approximately 24 Watts, the TRIACset point can have a value of approximately 28.

FIG. 9 depicts a two-dimensional graphical representation 900 includingonly the TRIAC set point values and electric power values. Asillustrated, an x-axis 902 lists a plurality of set point values and ay-axis 904 lists a plurality of electric power values. Thetwo-dimensional graphical representation 900 is a version of thethree-dimensional graphical representation 800, but is based on aconstant supply voltage, e.g., 110 V, 250 V, etc. As shown in thetwo-dimensional graphical representation 900, the curve 906 closelymatches the points 908, 910, and 912, which are examples of electricpower values at which the cooking device 10 can be operated. As such,the curve 808 and the curve 906, which represents various values thatcan be calculated using the second transfer function, show that at aparticular supply voltage and an electric power value, a controller 100can accurately determine a set point value for the TRIAC 78.

At block 608, the controller 100 applies the set point value on theTRIAC. The manner in which the set point is selected and utilized tocontrol the operating speed of the fan blades 82 is described in greaterdetail below.

FIG. 10 depicts a set point included as part of an alternating current(AC) waveform 1000. Broadly speaking, an AC waveform represents thebehavior of voltage and current in an alternating current (AC) basedelectrical system. In this system, which is implemented on the cookingdevice 10, supply voltage fluctuates at various time intervals from apositive voltage to a negative voltage, which in turn results in achange in the direction of the current (flow of electrons). Thefluctuation in voltage (i.e. electric potential) from the positivevoltage to the negative voltage and the resulting change in thedirection of the current due to this fluctuation generates the electricpower that is fundamental to operating various components of the cookingdevice 10, namely the controller 100 and the inductive load 80.

In the AC waveform 1000 of FIG. 10 , an x-axis 1002 corresponds to aplurality of time values (measured in seconds or milliseconds) and ay-axis 1004 corresponds to positive and negative voltage values. In someembodiments, as the supply voltage received by the power supply 110, asdescribed in block 602 above, is in the range of 104 V to 110 V, thepeak value 1006 of the AC waveform 1000 can be a value of, e.g.,approximately 120 V. The positive voltage value 1008 at this peak valuecan be approximately 120 V, depending on the precise value of the supplyvoltage received by the power supply 110. Similarly, the trough value1010 of the AC waveform 1000 can be a value of, e.g., (approximately−120 V). As such, the negative voltage value 1012 at this trough valuecan be either approximately −120 V. When the cooking device 10 is turnedon or is in operation, the controller 100 receives, the supply voltagefrom the power supply 110, which drivers or moves a particular amount ofcurrent in a sinusoidal direction. As stated above, the driving of thecurrent by the supply voltage in the sinusoidal orientation results inthe generation of electric power that operates various components of thecooking device.

Thereafter, as stated above, the controller 100 utilizes the secondtransform function to determine a set point of the TRIAC 78 and appliesthis set point to the TRIAC 78. The controller 100 can control theamount of electric power delivered to the inductive load 80 based on thevalue of the set point. Each set point value represents a portion or apercentage of the wave that is filtered or blocked by the TRIAC 78. Ifthe controller 100 applies a set point value of 0 for the TRIAC 78, theTRIAC 78 will transmit the entirety of the AC waveform 1000 that itreceived from the controller 100, to the inductive load 80. As a result,a maximum amount of electric power will be delivered to the inductiveload 80, which in turn will result in the generation of a large amountof mechanical rotational energy that is delivered to the fan blades 82.In contrast, if a higher set point value is determined and applied tothe TRIAC 78, a larger percentage of the AC waveform will be filtered orblock, and as a result, a smaller amount of mechanical rotational energywill be generated and delivered to the fan blades 82.

Returning to FIG. 10 , based on the selection and application of a setpoint (e.g., set point having a value of 30) by the controller 100, theTRIAC 78 filters or blocks a particular portion or percentage of thecurrent shown in AC waveform 1000 from being transmitted to theinductive load 80. The portion 1014 of the AC waveform 1000 that isblocked, based on the set point, is indicated by the dotted line in FIG.10 . In operation, the TRIAC 78 blocks the portion 1014 by abruptlyreducing the voltage from, e.g., the positive voltage value 1008 at thepeak value 1006 of the AC waveform 1000 to a voltage of 0. The TRIAC 78then maintains the 0 voltage value for a time frame 1016. When thevoltage of 0 is maintained, the current corresponding to the portion1014 is not transmitted to the inductive load 80, as there is no voltageavailable to drive the current. After a particular time frame, the TRIAC78 increases the voltage from 0 to a voltage value 1018, whichreinitiates the transfer of current to the inductive load 80. As such,the set point value of 30 represents the time frame 1016 during whichthe voltage is maintained at 0 V.

A large set point value, e.g., 70, results in a TRIAC 78 abruptlyreducing the voltage from a particular value to 0 V and maintaining thevoltage value at 0 V for a prolonged period of time, which results in asignificant portion of the current of the AC waveform 1000 from beingtransmitted to downstream components, e.g., the inductive load 80. Assuch, the controller 100 can operate to significantly reduce theoperating speed of the inductive load 80 by selecting and applying a setpoint of 70, and by extension, the operating speed of the fan blades 82.In contrast, the controller 100 can operate to increase the operatingspeed of the inductive load 80 by selecting and applying a set point of,e.g., 10, because such a set point results in the TRIAC 78 blocking arelatively small portion of the current of the AC waveform 1000 frombeing transmitted to the inductive load.

At block 610, the controller 100 adjusts operation of the inductive loadto the target power responsive to the application of the set point valueon the TRIAC 78. In embodiments, the operation of the inductive load 80at the target power causes the operation of the inductive load 80 at thetarget speed. For example, after the controller 100 applies the setpoint value on the TRIAC 78 as described above with respect to block610, the TRIAC 78 blocks a precise amount of current from the ACwaveform 1000. In other words, based on the set point value applied inblock 610, the TRIAC 78 enables a precise amount of current of the ACwave form 1000, and by extension, electric power, to flow to theinductive load 80, which results in the inductive load 80 generating aparticular amount of mechanical rotational energy that causes the fanblades 82 to rotate at the preprogrammed operating speed of, e.g., 1000RPM.

As explained above, the set point value that is applied to the TRIACcontrols the amount of current of the AC waveform 1000 that is suppliedto the inductive load 80, and by consequence, the operating speed of thefan blades 82. A large set point value (e.g., 70) that is selected andapplied on the TRIAC 78 results in a reduction in the operating speed ofthe fan blades 82 and a smaller set point value results in an increasein the operating seed of the fan blades 82.

Having described the manner in which the controller 100 utilizestransfer functions to determine a target power for operating theinductive load to control the operating speed of the fan 30, adescription of the transfer functions is instructive. Versions of thetransfer function that are utilized to determine the set point of theTRIAC 78 (e.g., the second transfer function) can be expressed asfollows:

$\begin{matrix}{{P_{{@\alpha}V}({PAT})} = {\frac{A}{E + {e\left( \frac{{PAT} + C}{B} \right)}} + D}} & (1)\end{matrix}$ $\begin{matrix}{{{AFP}\left( {{PAT},{SPV}} \right)} = {{\left( \frac{{P_{{@\alpha}V}({PAT})} - y_{0}}{\alpha - x_{o}} \right)\left( {{SPV} - x_{o}} \right)} + y_{0}}} & (2)\end{matrix}$ $\begin{matrix}{{{PAT}\left( {{SPV},{AFP}} \right)} = {{{\ln\left( {\frac{A}{\left( \frac{\left( {{AFP} - y_{0}} \right)*\left( {\alpha - x_{o}} \right)}{\left( {{SPV} - x_{o}} \right)} \right) + y_{0} - D} - E} \right)}*B} - C}} & (3)\end{matrix}$

As shown in expressions (1), (2), and (3), each expression includes aplurality of polynomials. It is noted that each of the above expressionsrepresent different versions of the second transfer function that isutilized to determine a set point of the TRIAC 78. As stated above, theset point of the TRIAC 78 is also referred to as a phase angle target orthe variable (PAT). The variables of A, B, C, D, E, x₀, y₀, and a areconstant values that are derived from data that is gathered frommonitoring the operation various components of the cooking device 100for a particular time frame. The expression (1) and (2) are utilized bythe controller 100 to determine an electric power that is delivered tothe inductive load 80 based on a known phase angle target (set point)anda constant supply voltage. Additionally, expression (3) is utilized bythe controller 100 to determine a phase angle target value (PAT) givenan input power and a supply voltage value. The input power value (e.g.,Apparent Power Value) can be defined as a target power value that isnecessary to ensure that the fan blades 82 operate at an operating speedthat is preprogrammed or hardwired into the memory 102 of the controller100, as described in blocks 604 and 606 above. However, it is noted thatcharacters or expressions other than polynomials can also be utilized ineach of the first and the second transfer functions in order toimplement the transfer function based electrical power delivery systemdescribed herein.

In addition, the expression (3) can be defined as a set two separateexpressions:

$\begin{matrix}{{{PAT}(\beta)} = {{{\ln\left( {\frac{A}{\beta + y_{o} - D} - E} \right)}*B} - C}} & (4)\end{matrix}$ $\begin{matrix}{{\beta\left( {{AFP},{SPV}} \right)} = \left( \frac{\left( {{AFP} - y_{o}} \right)*\left( {\alpha - x_{o}} \right)}{\left( {{SPV} - x_{o}} \right)} \right)} & (5)\end{matrix}$

Partitioning of the expression (3) into expressions (4) and (5) enablesdefining the function of PAT(AFT, SPV)—which is used to determine aphase angle target given the values of an electric power and a supplyvoltage—using a polynomial expression, which significantly reduces thespace allocation requirement in the memory 102 needed to implement orprocess expression (3). In some embodiments, a manner in which PAT ((3)is implemented and approximated is expressed by the followingexpression:PAT(β)≈PAT_(polyApprx)(β)=k ₃*β³ +k ₂*β² +k ₁ *β+/k ₀  (6)

The above expression also includes various polynomials that, whenprocessed by the controller 100, significantly reduce the spaceallocation requirement in the memory 102 needed to process expression(3). These polynomials are k₀, k₁, k₂, k₃, β, β², and β³. To generateexpressions (1)-(5), it is assumed that the relationship between thesupply voltage and the electric power that is utilized to control theoperating speed of the fan blades 82 share a linear relationship.Further, as described above, a reduction in the set point of the TRIAC78 results in a reduction of the electric power that is delivered to theinductive load 80, and by extension, the power (i.e. mechanicalrotational energy) that is delivered to the fan blades 82.

In some embodiments, the controller 100 implements a set of equations orexpressions that enable compensation for and reduction of losses inelectric power that may occur due to various environmental factors. Inother words, these expressions, shown below, enable power factorcompensation:

$\begin{matrix}{{E({PAT})} = \frac{\left( {c_{1} + {c_{2}*e^{c_{3}*x}}} \right)}{c_{1}}} & (7)\end{matrix}$PFP=AFP*E(PAT)  (8)

In the above expressions, the variable AFP represents the electric powerthat is delivered to the inductive load 80, which in turn results in thegeneration of the mechanical rotational energy that causes the fanblades 82 to run at a particular operating speed. The variable PFPcorrespond to practical fan power, which is a portion of the apparentpower that corresponds to power losses that occur due to the operationof the inductive load 80. The expressions (7) and (8) are onlyimplemented under particular conditions, which is illustrated in FIG. 11.

FIG. 11 depicts a non-linear relationship 1100 between operating speedsof the fan blades 82 based on variations in the set point of the TRIAC78. As illustrated in FIG. 11A, the x-axis 1102 lists a plurality ofelectric power values ranging from 0 to 45 Watts and the y-axis 1104lists a plurality of operating speeds of the fan blades 82 ranging from0 to 3000 RPM. As shown, when the electric power values are in a rangefrom 15 to 20 Watts, the operating speeds of the fan blades 82 rangefrom 1000 to 1500 RPM. However, when the electric power value isapproximately 24 Watts, the operating speeds of the fan blades 82 varysignificantly from 1000-2500 RPM. As such, the relationship between theset points and the operating speeds are not linear.

In contrast with FIG. 11 , FIG. 12 depicts a substantially linearrelationship 1200 between electric power values and operating speeds.FIG. 12 includes an x-axis 1202 that lists a plurality of electricalpower values ranging from 0 to 20 Watts and a y-axis 1204 that lists aplurality of operating speeds ranging from 0 to 2500 RPM. As shown inFIG. 12 , a number of points are positioned in close proximity to ordirectly on the fitting line 1206, indicating a clear linearrelationship between the electric power values and the operating speeds.

In order to accurately implement the transfer functions as shown inexpressions (1), (2), and (3), the parameters represented by variablesof A, B, C, D, E, x₀, y₀, and α are obtained by the controller 100 byanalyzing trends associated with the supply voltage and electric powerdelivered to the inductive load 80. One trend that is analyzed is therelationship between electric power delivered to the inductive load 80(apparent power) and the supply voltage.

FIG. 13A depicts a graphical representation 1300 that shows arelationship between supply voltages and electric power values atvarious set points. The x-axis 1302 lists supply voltages ranging from 0to 130 Volts and the y-axis 1304 lists electric power values rangingfrom 4 Watts to 20 Watts. Further, various subsets of points areindicated with a different color and each color corresponds to aspecific phase angle target value or set point value of the TRIAC 78(e.g., as shown in box 1306 and the graphical representation 1300). Inorder to determine two of the parameters—x₀ and y₀—a plurality ofdiagonal fitting lines may be to determine the relationship betweenelectric power values and supply voltages at each set point, as shown inFIG. 13B. In FIG. 13B, a graphical representation 1307 depicts fittinglines 1308, 1310, 1312, 1314, 1316, and 1318 that are generated in orderto determine the relationship between electric power values and supplyvoltages at set point values (phase angle target values) of 0, 12, 18,21, 24, and 27. As indicated by these fitting lines, the relationshipbetween the supply voltages and the electric power values issubstantially linear. Thereafter, to determine the value of theparameters of x₀ and y₀, a point where the fitting lines 1308, 1310,1312, 1314, 1316, and 1318 intersect is determined by the controller100. Such an intersection point is depicted in FIG. 13C.

FIG. 13C illustrates a graphical representation 1320 in which aplurality of additional supply voltage values are added to the x-axis1302 and a plurality of additional electric power values are added tothe y-axis 1304. The graphical representation 1320 also includes and anintersection point 1322 of various fitting lines. Specifically, thex-axis 1302 in FIG. 13C includes values ranging from 20 V to 130 V andthe y-axis 1304 includes values ranging from −10 to 20 Watts. Further,the intersection point 1322 of the fitting lines 1308, 1310, 1312, 1314,1316, and 1318 is indicated in FIG. 13C. This intersection point 1322corresponds to the values of x₀ and y₀. In aspects, the value of x₀ andy₀ can be 28.29 and −8.46, respectively. However, it is noted the valuesof x₀ and y₀ can vary significantly based on differing characteristicsacross various systems.

Additionally, other trends can be analyzed by the controller 100 todetermine the value of the parameters A, B, C, D, E, and α.

FIG. 14 depicts a graphical representation 1400 that shows arelationship between set points of the TRIAC 78 and the electric powervalues at these set points. The x-axis 1402 lists a plurality of setpoint values ranging from 0 to 35 and the y-axis 1404 lists a pluralityof electric power values, namely the electric power values delivered tothe inductive load 80. These values range from 5 to 20 Watts. Further, aconstant supply voltage that is delivered to controller 100 while thecontroller 100 applies a subset of the range of set points listed on thex-axis 1402 corresponds to the a value. In some embodiment, the a valuecan be approximately 112 V.

Thereafter, the controller 100 can apply a sigmoid function 1500 to thedata depicted in the graphical representation 1400, as illustrated inFIG. 15 . The sigmoid function 1500 can be represented by the followingexpression:

$\begin{matrix}{{\sigma(z)} = \ \frac{1}{1 + e^{- x}}} & (9)\end{matrix}$

Part of the application of the sigmoid function 1500 to the dataincludes replacing various values in expression (9) with parameters orcoefficients of A, B, C, D, E such that the expression (9) can bereplaced by the following expression:

$\begin{matrix}{{P_{{@\alpha}V}({PAT})} = {\frac{A}{E + {e\left( \frac{{PAT} + C}{B} \right)}} + D}} & (10)\end{matrix}$

Thereafter, an optimization problem can be designed and solved by thecontroller 100 to generate a line that fits the data that is used togenerate the graphical representation 1400. The optimization problem issolved by the controller 100 in order to minimize an amount of variancein the data. With respect to the optimization problem, it is noted thatin order to determine the values of parameters or coefficients A, B, C,D, and E, a least squares error analysis can be performed. Theimplementation of the least squares error analysis enables for thedetermination of specific values for the parameters or coefficients A,B, C, D, and E that ensure that a specific set of data points closelyfit the expression 10 (i.e. equation 10).

FIG. 16 depicts a graphical representation 1600 that includes a line1602 that fits the data used to generate the graphical representation1400. The values of each of the coefficients A, B, C, D, E can bederived from the line 1902.

In some embodiments, the temperature sensor 74, as stated above, isconfigured to measure a temperature of the interior of the fuel boxassembly 60 and route the temperature data to the memory 102 of thecontroller 100. This temperature data can be analyzed by the controller100 to determine the overall temperature of the cooking device 10 andthe components disposed therein including, e.g., the inductive load 80.In some embodiments, if the temperature data measured by the controller100 is below a threshold value such as, e.g., ambient temperature orroom temperature in the range of 59 degrees to 77 degrees (15, thecontroller 100 can determine that the cooking device 10 is in a coldstate. As defined above, a cold state is when the cooking device 10 hasnot been recently used, e.g., has been off for a long period of timesuch as several hours.

When the cooking device 10 is initiated (e.g., turned on) from such astate, the controller 100, automatically and without user intervention,can initiate a starting condition compensation algorithm. Uponinitiation of this algorithm, the controller 100 enables the applicationof a substantial amount electric power (e.g., high starting electricpower) to the inductive load 80. The controller 100 then applies alinear decaying value to this starting electric power, over a particulartime frame, to modify the electric power delivered to the inductive load82. As a result, the electric power gradually regulates to the electricpower that enables the fan blades 82 to operate at an operating speedthat is preprogrammed into the memory 102, e.g., 1000 RPM. An expressionthat represents the linearly decaying value is as follows:

$\begin{matrix}{{P_{cold\_ motor}(t)} = {P_{hot\_ motor}*\left( {1 + {R_{comp}\frac{\left( {t_{comp} - t} \right)}{t_{comp}}}} \right)}} & (11)\end{matrix}$

In the above expression, the variable P_(cold_motor) represents anamount of electric power that is delivered to the inductive load 80 uponcompletion of the application of the linear decaying value over aparticular time frame. The variable P_(hot_motor) represents a powervalue that is required to generate the electric power that enables theinductive load 80 to operate at a particular target operating speedunder, e.g., the condition that the inductive load 80 of the cookingdevice is operating at or satisfies a temperature threshold, e.g. theinductive load 80 operates at a temperature that can be classified aswarm. The variable of R_(comp) represents maximum multiplier ratio andt_(comp) represents the time period over which the linearly decayingvalue is applied. It is noted that, while a linearly decaying value isdescribed in expression 11, a non-linear decaying value such as anexponential value can also be utilized. In other words, the controller110 can apply an exponential decaying value to a starting electricpower, over a particular time frame, in order to modify the electricalpower delivered to the inductive load 82.

FIG. 17 depicts a graphical representation 1700 of an electric powerdelivered to an inductive load 80 upon which the linearly decaying valueis applied over a particular time frame, according to some embodimentsdescribed and illustrated herein. When the cooking device 10 is turnedon from a cold state, a large amount of electric power is initiallydelivered to the inductive load 80. When the cooking device 10 isactivated from the cold state, the amount of the electric power that isdelivered is gradually reduced and maintained at a particular level, asshown in FIG. 17 . In FIG. 17 , the x-axis 1702 corresponds to timeperiods and the y-axis 1704 corresponds to electric power values. Insome embodiments, the cooking device 10 is determined to be in the coldstate if the temperature sensor 74 detects the temperature of thecooking device 10 to be in a threshold temperature range of 15° C. to50° C. In some embodiments, a single threshold temperature value (e.g.,21° C.) can be utilized by the controller 100.

FIG. 18 depicts a graphical representation 1800 of the operating speedof the inductive load 80 based on the gradual reduction of the electricpower delivered to the inductive, as illustrated in FIG. 17 anddescribed above. It is noted that FIG. 18 should be interpreted incombination with FIG. 17 . As shown in FIG. 18 , when the cooking device10 is turn on from a cold state and a large amount of electric power isinitially delivered to the inductive load 80, there is a sudden andexponential increase in the operating speed of the inductive load,causing a similar increase in the operating speed of the fan blades 82.Thereafter, as shown in FIG. 18 , the operating speed of the inductiveload plateaus and is maintained at a particular level based on a steadyamount of electric power being delivered to the inductive load 80 asillustrated in FIG. 17 . In FIG. 18 , the x-axis 1802 corresponds totime periods and the y-axis 1804 corresponds to operating speeds of theinductive load 80.

As explained above, in some embodiments, the controller 100 can monitorthe length of time during which the igniter 66 is activated. As such,the controller 100 can be configured to determine whether a total lengthof time during which the igniter is activated exceeds the determinedmaximum time of activation. In response to determining that the totallength of time exceeds the determined maximum time of activation, thecontroller 100 can cause the igniter 66 to deactivate and the cookingdevice 10 to exit the ignition mode.

Additionally, in some embodiments, the controller 100 can cause theigniter 66 to deactivate and the cooking device 10 to exit the ignitionmode in response to various events during the operation of the cookingdevice 10. For example, the controller 100 can deactivate igniter 66 candeactivated and cause the cooking device 10 to exit the ignition mode inresponse to a user of the cooking device 10 pressing a start/stop buttonon the user interface 40 and/or in response to a user of the devicechanging the operating mode of the cooking device 10, via interactionwith the user interface 40, from a smoker operating mode to an infusionoperating mode.

FIG. 19 is a block diagram 1900 of a computing system 1910 suitable foruse in implementing the computerized components described herein. Inbroad overview, the computing system 1910 includes at least oneprocessor 1950 for performing actions in accordance with instructions,and one or more memory devices (e.g., cache 1960 and/or memory 1970) forstoring instructions and data. The illustrated example computing system1910 includes one or more processors 1950 in communication, via a bus1915, with memory 1970 and with at least one network interfacecontroller 1920 with a network interface 1925 for connecting to externaldevices 1930, e.g., a computing device. The one or more processors 1950are also in communication, via the bus 1915, with each other and withany I/O devices at one or more I/O interfaces 1940, and any otherdevices 1980. The processor 1950 illustrated incorporates, or isdirectly connected to, cache 1960. Generally, a processor will executeinstructions received from memory. In some embodiments, the computingsystem 1910 can be configured within a cloud computing environment, avirtual or containerized computing environment, and/or a web-basedmicroservices environment.

In more detail, the processor 1950 can be any logic circuitry thatprocesses instructions, e.g., instructions fetched from the memory 1970or cache 1960. In many embodiments, the processor 1950 is an embeddedprocessor, a microprocessor unit or special purpose processor. Thecomputing system 1910 can be based on any processor, e.g., suitabledigital signal processor (DSP), or set of processors, capable ofoperating as described herein. In some embodiments, the processor 1950can be a single core or multi-core processor. In some embodiments, theprocessor 1950 can be composed of multiple processors.

The memory 1970 can be any device suitable for storing computer readabledata. The memory 1970 can be a device with fixed storage or a device forreading removable storage media. Examples include all forms ofnon-volatile memory, media and memory devices, semiconductor memorydevices (e.g., EPROM, EEPROM, SDRAM, flash memory devices, and all typesof solid state memory), magnetic disks, and magneto optical disks. Acomputing system 1910 can have any number of memory 1970.

The cache 1960 is generally a form of high-speed computer memory placedin close proximity to the processor 1950 for fast read/write times. Insome implementations, the cache 1960 is part of, or on the same chip as,the processor 1950.

The network interface controller 1920 manages data exchanges via thenetwork interface 1925. The network interface controller 1920 handlesthe physical, media access control, and data link layers of the OpenSystems Interconnect (OSI) model for network communication. In someimplementations, some of the network interface controller's tasks arehandled by the processor 1950. In some implementations, the networkinterface controller 1920 is part of the processor 1950. In someimplementations, the computing system 1910 has multiple networkinterface controllers 1920. In some implementations, the networkinterface 1925 is a connection point for a physical network link, e.g.,an RJ 45 connector. In some implementations, the network interfacecontroller 1920 supports wireless network connections and an interfaceport 1925 is a wireless Bluetooth transceiver. Generally, a computingsystem 1910 exchanges data with other external devices (the externaldevices 1930) via physical or wireless links to a network interface1925. In some implementations, the network interface controller 1920implements a network protocol such as LTE, TCP/IP Ethernet, IEEE 802.11,IEEE 802.16, Bluetooth, or the like.

The other computing device 1930 is connected to the computing system1910 via a network interface port 1925. The other computing device 1930can be a peer computing device, a network device, a server, or any othercomputing device with network functionality. In some embodiments, thecomputing device 1930 can be a network device such as a hub, a bridge, aswitch, or a router, connecting the computing system 1910 to a datanetwork such as the Internet.

In some uses, the I/O interface 1940 supports an input device and/or anoutput device (not shown). In some uses, the input device and the outputdevice are integrated into the same hardware, e.g., as in a touchscreen. In some uses, such as in a server context, there is no I/Ointerface 1940 or the I/O interface 1940 is not used. In some uses,other devices 1980 are in communication with the computing system 1910,e.g., external devices connected via a universal serial bus (USB).

The other devices 1980 can include an I/O interface 1940, externalserial device ports, and any additional co-processors. For example, acomputing system 1910 can include an interface (e.g., a universal serialbus (USB) interface, or the like) for connecting input devices (e.g., akeyboard, microphone, mouse, or other pointing device), output devices(e.g., video display, speaker, refreshable Braille terminal, orprinter), or additional memory devices (e.g., portable flash drive orexternal media drive). In some implementations, an I/O device isincorporated into the computing system 1910, e.g., a touch screen on atablet device. In some implementations, a computing system 1910 includesan additional device 880 such as a co-processor, e.g., a mathco-processor that can assist the processor 1950 with high precision orcomplex calculations.

One or more aspects or features of the subject matter described hereincan be realized in digital electronic circuitry, integrated circuitry,specially designed application specific integrated circuits (ASICs),field programmable gate arrays (FPGAs) computer hardware, firmware,software, and/or combinations thereof. These various aspects or featurescan include implementation in one or more computer programs that areexecutable and/or interpretable on a programmable system including atleast one programmable processor, which can be special or generalpurpose, coupled to receive data and instructions from, and to transmitdata and instructions to, a storage system, at least one input device,and at least one output device. The programmable system or computingsystem may include clients and servers. A client and server aregenerally remote from each other and typically interact through acommunication network. The relationship of client and server arises byvirtue of computer programs running on the respective computers andhaving a client-server relationship to each other.

These computer programs, which can also be referred to as programs,software, software applications, applications, components, or code,include machine instructions for a programmable processor, and can beimplemented in a high-level procedural language, an object-orientedprogramming language, a functional programming language, a logicalprogramming language, and/or in assembly/machine language. As usedherein, the term “machine-readable medium” refers to any computerprogram product, apparatus and/or device, such as for example magneticdiscs, optical disks, memory, and Programmable Logic Devices (PLDs),used to provide machine instructions and/or data to a programmableprocessor, including a machine-readable medium that receives machineinstructions as a machine-readable signal. The term “machine-readablesignal” refers to any signal used to provide machine instructions and/ordata to a programmable processor. The machine-readable medium can storesuch machine instructions non-transitorily, such as for example as woulda non-transient solid-state memory or a magnetic hard drive or anyequivalent storage medium. The machine-readable medium can alternativelyor additionally store such machine instructions in a transient manner,such as for example as would a processor cache or other random accessmemory associated with one or more physical processor cores.

To provide for interaction with a user, one or more aspects or featuresof the subject matter described herein can be implemented on a computerhaving a display device, such as for example a cathode ray tube (CRT) ora liquid crystal display (LCD) or a light emitting diode (LED) monitorfor displaying information to the user and a keyboard and a pointingdevice, such as for example a mouse or a trackball, by which the usermay provide input to the computer. Other kinds of devices can be used toprovide for interaction with a user as well. For example, feedbackprovided to the user can be any form of sensory feedback, such as forexample visual feedback, auditory feedback, or tactile feedback; andinput from the user may be received in any form, including, but notlimited to, acoustic, speech, or tactile input. Other possible inputdevices include, but are not limited to, touch screens or othertouch-sensitive devices such as single or multi-point resistive orcapacitive trackpads, voice recognition hardware and software, opticalscanners, optical pointers, digital image capture devices and associatedinterpretation software, and the like.

Certain exemplary implementations have been described to provide anoverall understanding of the principles of the structure, function,manufacture, and use of the systems, devices, and methods disclosedherein. One or more examples of these implementations have beenillustrated in the accompanying drawings. Those skilled in the art willunderstand that the systems, devices, and methods specifically describedherein and illustrated in the accompanying drawings are non-limitingexemplary implementations and that the scope of the present invention isdefined solely by the claims. The features illustrated or described inconnection with one exemplary implementation may be combined with thefeatures of other implementations. Such modifications and variations areintended to be included within the scope of the present invention.Further, in the present disclosure, like-named components of theimplementations generally have similar features, and thus within aparticular implementation each feature of each like-named component isnot necessarily fully elaborated upon.

Approximating language, as used herein throughout the specification andclaims, may be applied to modify any quantitative representation thatcould permissibly vary without resulting in a change in the basicfunction to which it is related. Accordingly, a value modified by a termor terms, such as “about,” “approximately,” and “substantially,” are notto be limited to the precise value specified. In at least someinstances, the approximating language may correspond to the precision ofan instrument for measuring the value. Here and throughout thespecification and claims, range limitations may be combined and/orinterchanged, such ranges are identified and include all the sub-rangescontained therein unless context or language indicates otherwise.

One skilled in the art will appreciate further features and advantagesof the invention based on the above-described implementations.Accordingly, the present application is not to be limited by what hasbeen particularly shown and described, except as indicated by theappended claims. All publications and references cited herein areexpressly incorporated by reference in their entirety.

What is claimed is:
 1. A cooking device, comprising: a housing having abase defining a hollow cooking chamber and a movable cover coupled tothe base, the movable cover configured to cover an opening in thehousing to the hollow cooking chamber; a smoke unit coupled to thehousing, the smoke unit including a fuel box defining an interiorchamber in fluid communication with the hollow cooking chamber, and anigniter proximate the fuel box and configured to ignite fuel containedin the fuel box; and an electronic controller in operable communicationwith the igniter, the electronic controller configured to determine anaverage rate of energy supplied to the igniter during a predeterminedperiod of time of activation of the igniter and during an initialignition operating mode of the igniter, determine an average temperatureof a region proximate the igniter during the predetermined period oftime, and adjust a maximum time of activation of the igniter when theigniter is operating in the initial ignition operating mode during asubsequent period of time following the predetermined period of timebased on the determined average rate of energy and the determinedaverage temperature.
 2. The cooking device of claim 1, wherein theelectronic controller is configured to adjust the maximum time ofactivation of the igniter based on an operating mode of the smoke unit.3. The cooking device of claim 1, further comprising a fan coupled tothe housing, in fluid communication with the fuel box, and in operablecommunication with the electronic controller, wherein the electroniccontroller is configured to adjust an amount of power delivered to thefan during the initial ignition operating mode.
 4. The cooking device ofclaim 3, wherein the electronic controller is configured to adjust theamount of power delivered to the fan when a difference between atemperature of the region proximate the igniter and a temperature of airwithin the hollow cooking chamber is less than or equal to apredetermined temperature difference threshold.
 5. The cooking device ofclaim 3, wherein the electronic controller is configured to adjust theamount of power delivered to the fan when the temperature of the airwithin the hollow cooking chamber is less than a predeterminedtemperature threshold.
 6. The cooking device of claim 3, wherein theelectronic controller is configured to adjust the amount of powerdelivered to the fan when the rate of energy supplied to the igniter isless than a predetermined threshold.
 7. The cooking device of claim 1,wherein the movable cover is in the form of a lid or door.